KR102169298B1 - Method of fabricating a flexible substrate and the flexible substrate - Google Patents

Abstract

A method of manufacturing a flexible substrate and a flexible substrate manufactured thereby are provided. The method includes the steps of: printing a gate catalyst pattern on a separation layer, and forming a gate plating pattern on the gate catalyst pattern; Forming a gate insulating layer on the gate plating pattern; And printing a source catalyst pattern and a drain catalyst pattern spaced apart from each other on the gate insulating layer, and forming a source plating pattern and a drain plating pattern on the source catalyst pattern and the drain catalyst pattern, respectively.

Description

Method of fabricating a flexible substrate, and a flexible substrate manufactured thereby

The present invention relates to a method of manufacturing a flexible substrate and a flexible substrate manufactured thereby, and more particularly, to a method of manufacturing a flexible substrate including a thin film transistor, and a flexible substrate manufactured thereby.

With the development of the electronic industry, various electronic products are being developed. Recently, various electronic products having flexible characteristics have been introduced, and the flexible electronic products can be variously used in portable electronic devices as well as wearable IT devices. The flexible display includes a substrate (backplane) including a metal wiring and a thin film transistor array. In addition, circuits of many electronic products include metal wiring and thin film transistor arrays. Electronic circuits including such metal wires and thin film transistor arrays are used as various flexible electronic devices including flexible displays.

The manufacturing process of a conventional flexible substrate has a disadvantage in that a lot of materials and wastewater are discharged, including an etching process, and various processes such as deposition, mask formation, and etching are complicated, and the process cost is high. Or, in the conventional manufacturing process of flexible substrates, electrodes are formed by a printing method, but a metal paste containing fine metal particles is very expensive, it is difficult to obtain the reliability of the pattern, and there is a possibility that unwanted substances may be deposited outside the pattern. There are drawbacks.

The problem to be solved by the present invention is to provide a method of manufacturing a flexible substrate capable of reducing manufacturing cost.

Another problem to be solved by the present invention is to provide a flexible substrate with improved reliability.

A method of manufacturing a flexible substrate according to the present invention for achieving the above object comprises: forming a separation layer on the front surface of a carrier substrate; Printing a gate catalyst pattern on the separation layer and forming a gate plating pattern on the gate catalyst pattern; Forming a gate insulating layer on the gate plating pattern; Printing a source catalyst pattern and a drain catalyst pattern spaced apart from each other on the gate insulating layer, and forming a source plating pattern and a drain plating pattern on the source catalyst pattern and the drain catalyst pattern, respectively; Forming an active pattern covering the source plating pattern, the drain plating pattern, and the gate insulating layer exposed therebetween; Forming a first flexible substrate film covering the entire surface of the carrier substrate on which the active pattern is formed; And removing the separation layer and the carrier substrate.

The forming of the gate insulating layer may include printing and heat treating a precursor solution of a material constituting the gate insulating layer.

Before forming the gate catalyst pattern, the method may further include forming a second flexible substrate film on the separation layer.

The method may further include forming a back channel defense layer covering the active pattern before forming the first substrate layer.

The method may further include, before forming the first substrate layer, forming a gas barrier layer covering the entire surface of the carrier substrate on which the active pattern is formed.

The method may further include forming a protective film covering at least a portion of the first substrate film after removing the carrier substrate.

Preferably, the separation layer may be formed of a material different from that of the gate plating pattern.

The flexible substrate according to the present invention for achieving the above other object comprises: a first substrate film; An active pattern disposed in the first substrate film; A source electrode and a drain electrode disposed in the first substrate layer and spaced apart from each other by the active pattern; A gate electrode disposed in the first substrate film and spaced apart from the source electrode and the drain electrode; And a gate insulating layer interposed between the gate electrode and the source electrode and between the gate electrode and the drain electrode, wherein the gate electrode includes a gate catalyst pattern and a gate plating pattern, and the source electrode includes a source catalyst pattern and And a source plating pattern, and the drain electrode includes a drain catalyst pattern and a drain plating pattern.

The gate catalyst pattern may have an upper surface coplanar with the upper surface of the first substrate layer.

Upper surfaces of the source catalyst pattern and the drain catalyst pattern may be coplanar with the upper surface of the active pattern.

The flexible substrate may further include a second substrate layer disposed on the first substrate layer and in contact with the gate catalyst pattern.

The flexible substrate may further include a back channel protective layer interposed between the first substrate layer and the active pattern.

The flexible substrate may include between the first substrate layer and the active pattern, between the first substrate layer and the source electrode, between the first substrate layer and the drain electrode, between the first substrate layer and the gate insulating layer, and the A gas barrier layer interposed between the first substrate layer and the gate electrode may be further included.

The flexible substrate may further include a protective film disposed on at least a portion of the first substrate film.

The method of manufacturing a flexible substrate according to embodiments of the present invention can reduce process cost. The flexible substrate according to the embodiments of the present invention may have improved reliability.

1 to 5 are cross-sectional views illustrating a manufacturing process of a flexible substrate according to embodiments of the present invention.
6 to 10 are cross-sectional views of a flexible substrate according to embodiments of the present invention.

The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments related to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In the present specification, when it is mentioned that a certain component is on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. In addition, in the drawings, the thickness of the components is exaggerated for effective description of the technical content.

Embodiments described herein will be described with reference to cross-sectional views and/or plan views, which are ideal exemplary views of the present invention. In the drawings, the thicknesses of films and regions are exaggerated for effective description of technical content. Therefore, the shape of the exemplary diagram may be modified by manufacturing technology and/or tolerance. Accordingly, embodiments of the present invention are not limited to the specific form shown, but also include a change in form generated according to the manufacturing process. For example, the etched region shown at a right angle may be rounded or may have a shape having a predetermined curvature. Accordingly, regions illustrated in the drawings have properties, and the shapes of regions illustrated in the drawings are for exemplifying a specific shape of the region of the device and are not intended to limit the scope of the invention. In various embodiments of the present specification, terms such as first and second are used to describe various elements, but these elements should not be limited by these terms. These terms are only used to distinguish one component from another component. The embodiments described and illustrated herein also include complementary embodiments thereof.

The terms used in the present specification are for describing exemplary embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, "comprise" and/or "comprising" does not exclude the presence or addition of one or more other components.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings.

1 to 5 are cross-sectional views illustrating a manufacturing process of a flexible substrate according to embodiments of the present invention.

Referring to FIG. 1, first, a carrier substrate 100 may be prepared. The carrier substrate 100 may be a substrate having a solid and flat surface such as a glass substrate or a silicon wafer. After washing and drying the carrier substrate 100, the separation layer 102 may be formed on the carrier substrate 100. The separation layer 102 may be formed by, for example, a deposition process. Specifically, the separation layer 102 is made of at least one material selected from the group including copper, chromium, nickel, titanium, molybdenum, tungsten, manganese, silver, gold, platinum, tin, and silicon, or an alloy thereof. Can be formed.

Referring to FIG. 2, a gate catalyst pattern 104 may be printed on the separation layer 102. The gate catalyst pattern 104 may be formed by printing a catalyst solution that promotes a chemical reaction in a subsequent plating process. At this time, the solvent in the catalyst solution evaporates and only the catalyst may remain on the separation layer 102. When plating copper, a solution containing palladium may be used as the catalyst solution. Alternatively, when nickel is to be plated, a solution containing nickel may be used as the catalyst solution. For example, the gate catalyst pattern 104 may include palladium or nickel. The gate catalyst pattern 104 may be formed to expose a part of the separation layer 102.

Subsequently, referring to FIG. 2, a plating process such as electroless plating may be performed to form a gate plating pattern 106 on the gate catalyst pattern 104. That is, by immersing the carrier substrate 100 on which the gate catalyst pattern 104 is formed in a plating solution, a metal reduction reaction occurs only on the gate catalyst pattern 104 to form the gate plating pattern 106. The gate plating pattern 106 may be formed to cover a side surface of the gate catalyst pattern 104 as well. The gate plating pattern 106 may be formed of at least one metal selected from a group including copper, nickel, platinum, gold, and chromium. Preferably, the gate plating pattern 106 may be formed of a metal different from that of the separation layer 102. The gate plating pattern 106 and the gate catalyst pattern 104 may constitute a gate electrode GE. The carrier substrate 100 on which the gate electrode GE is formed may be washed again and dried. By appropriately selecting a material of the separation layer 102 and a type of material constituting the gate electrode GE, the bonding force between the separation layer 102 and the gate electrode GE may be adjusted to decrease.

Referring to FIG. 3, a gate insulating layer 107 covering the gate electrode GE and the separation layer 102 may be formed. The gate insulating layer 107 may be formed by printing a precursor solution of a material constituting the gate insulating layer 107 and heat treatment. During the heat treatment process, the precursor may be decomposed to become a material constituting the gate insulating layer 107. The gate insulating layer 107 may be formed by printing a solution containing a precursor of silicon oxide (SiO2) such as polysilazane, polysiloxane, or tetraethyl orthosilicate, drying, and heat treatment. . As another example, the gate insulating layer 107 may be formed by printing a solution including a precursor of aluminum oxide (Al2O3) such as trimethylaluminium, drying, and heat treatment. As another example, the gate insulating layer 107 may be formed by printing a solution containing a precursor of an oxide having good insulating properties such as zirconium oxide (ZrO2) or titanium oxide (TiO2), drying, and heat treatment. As another example, the gate insulating layer 107 may be formed by printing and curing a polymer having good insulating properties. The gate insulating layer 107 is preferably made of a material having a low bonding strength with the separation layer 102.

Subsequently, referring to FIG. 3, a source catalyst pattern 108s and a drain catalyst pattern 108d spaced apart from each other may be printed on the gate insulating layer 107. The source catalyst pattern 108s and the drain catalyst pattern 108d may be formed by printing a catalyst solution that promotes a chemical reaction in a subsequent plating process. At this time, the solvent in the catalyst solution evaporates, and only the catalyst may remain on the gate insulating layer 107. When plating copper, a solution containing palladium may be used as the catalyst solution. Alternatively, when nickel is to be plated, a solution containing nickel may be used as the catalyst solution. For example, the source catalyst pattern 108s and the drain catalyst pattern 108d may include palladium or nickel.

Subsequently, referring to FIG. 3, a plating process such as electroless plating is performed to form a source plating pattern 110s and a drain plating pattern 110d on the source catalyst pattern 108s and the drain catalyst pattern 108d, respectively. Can be formed. That is, metal reduction only on the source catalyst pattern 108s and the drain catalyst pattern 108d by immersing the carrier substrate 100 on which the source catalyst pattern 108s and the drain catalyst pattern 108d are formed in a plating solution. A reaction may occur to form the source plating pattern 110s and the drain plating pattern 110d. The source plating pattern 110s and the drain plating pattern 110d may be formed to cover side surfaces of the source catalyst pattern 108s and the drain catalyst pattern 108d, respectively. The source plating pattern 110s and the drain plating pattern 110d may be formed of at least one metal selected from a group including copper, nickel, platinum, gold, and chromium. Preferably, the source plating pattern 110s and the drain plating pattern 110d may be formed of a metal having good bonding strength with the gate insulating layer 107. The source catalyst pattern 108s and the source plating pattern 110s may constitute a source electrode SE. The drain catalyst pattern 108d and the drain plating pattern 110d may constitute a drain electrode DE. The carrier substrate 100 on which the source electrode SE and the drain electrode DE are formed may be washed again and dried.

Referring to FIG. 4, an active pattern 112 may be formed to cover the source electrode SE, the drain electrode DE, and the gate insulating layer 107 exposed therebetween. The active pattern 112 may also be formed by printing a precursor solution of a material constituting the active pattern 112 and heat treatment. The active pattern 112 may be formed of at least one material selected from the group including zinc oxide, tin oxide, zinc tin oxide, aluminum zinc oxide, indium zinc oxide, and silicon. Alternatively, the active pattern 112 may be formed by printing a solution containing an organic semiconductor material such as pentacene and heat treatment.

With continued reference to FIG. 4, a substrate layer 114 may be formed on the entire surface of the carrier substrate 100 on which the active pattern 112 is formed. The substrate layer 114 may be formed of a flexible material. For example, the substrate film 114 may be formed by coating and curing a flexible substrate material. As the flexible substrate material, at least one material selected from the group including acrylate resin, urethane resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyimide resin, polyester resin, and silicone resin Can include. The substrate film 114 may include a material having low adhesion to the separation layer 102. Accordingly, the flexible substrate 200 may be formed on the separation layer 102. That is, the flexible substrate 200 includes the gate electrode GE, the gate insulating layer 107, the source electrode SE, the drain electrode DE, the active pattern 112, and the substrate layer 114. It may include.

Referring to FIG. 5, the flexible substrate 200 on the separation layer 102 may be removed. Accordingly, the flexible substrate 200 including the thin film transistor array may be completed. Since the bonding strength between the separation layer 102 and the gate electrode GE, between the separation layer 102 and the gate insulating layer 107 and between the separation layer 102 and the substrate layer 114 is low, Removing the flexible substrate 200 may simply use mechanical force. This eliminates the need for expensive and complex laser lift-off processes, reducing manufacturing costs and simplifying the process.

In the method of manufacturing a flexible substrate according to embodiments of the present invention, a printing method may be used without using an etching process to form patterns. This eliminates the need for expensive photo mask production or photolithography process. In addition, the problem of a large amount of wastewater generated in the etching process can also be solved. In addition, when forming the gate electrode, the source electrode, and the drain electrode, since a catalyst printing and plating process are used, an expensive metal paste used in an existing printing process is not required, and process cost can be reduced.

In addition, in the method of manufacturing a flexible substrate according to embodiments of the present invention, all thin film transistor manufacturing processes are performed before applying the substrate film 114 made of a polymer. Therefore, the material of the substrate layer 114 is not limited by the temperature of the heat treatment process during thin film transistor manufacturing processes. This eliminates the need to use polyimide that is expensive and stable at high temperatures as the material of the substrate film 114. That is, as the substrate layer 114, various polymer materials having a low process temperature and low cost can be used. In addition, since the temperature of the heat treatment process during the manufacturing process of the thin film transistor can be increased regardless of the material of the substrate film 114, electrical characteristics of the thin film transistor can be improved.

6 to 10 are cross-sectional views of a flexible substrate according to embodiments of the present invention.

Referring to FIG. 6, when the flexible substrate 200 removed in FIG. 5 is turned over, the active pattern 112, the source electrode SE, the drain electrode DE, and the gate insulating layer 107 are in the substrate layer 114. , The gate electrode GE may be disposed. The gate electrode GE may include a gate catalyst pattern 104 and a gate plating pattern 106. The source electrode SE may include a source catalyst pattern 108s and a source plating pattern 110s. The drain electrode DE may include a drain catalyst pattern 108d and a drain plating pattern 110d. The gate catalyst pattern 104 may have an upper surface coplanar with the upper surface of the substrate layer 114. Upper surfaces of the source catalyst pattern 108s and the drain catalyst pattern 108d may be coplanar with the upper surface of the active pattern 112. Some of the source electrode SE and the drain electrode DE may be connected to a data line. The gate electrode GE, the source electrode SE, the drain electrode DE, and the active pattern 112 may constitute one thin film transistor. A plurality of thin film transistors may be disposed to form an array.

Referring to FIG. 7, the flexible substrate 200a according to the present example may further include an auxiliary substrate layer 120 disposed on the substrate layer 114 and in contact with the gate catalyst pattern 104. The auxiliary substrate layer 120 may be formed on the separation layer 102 before forming the gate electrode GE in the step of FIG. 1. The auxiliary substrate layer 120 may be formed by printing a precursor solution of a material constituting the auxiliary substrate layer 120 and heat treatment. During the heat treatment process, the precursor may be decomposed to become a material constituting the auxiliary substrate layer 120. The auxiliary substrate film 120 may be formed by printing a solution containing a precursor of silicon oxide (SiO2) such as polysilazane, polysiloxane, or tetraethyl orthosilicate, drying, and heat treatment. have. As another example, the auxiliary substrate layer 120 may be formed by printing a solution including a precursor of aluminum oxide (Al2O3) such as trimethylaluminium, drying, and heat treatment. As another example, the auxiliary substrate layer 120 may be formed by printing a solution including a precursor of an oxide having good insulating properties such as zirconium oxide (ZrO2) or titanium oxide (TiO2), drying, and heat treatment. As another example, the auxiliary substrate film 120 may be formed by printing and curing a polymer having good insulating properties. It is preferable that the auxiliary substrate film 120 be formed of a material having a low adhesion to the separation layer 102.

Referring to FIG. 8, the flexible substrate 200b according to the present example may further include a back channel protective layer 122 interposed between the substrate layer 114 and the active pattern 112. The back channel protective layer 122 may be formed before forming the substrate layer 114 in the step of FIG. 4. The back channel defense layer 122 may be formed by printing a precursor solution of a material constituting the back channel defense layer 122 and heat treatment. During the heat treatment process, the precursor may be decomposed to become a material constituting the back channel protective layer 122. The back channel protective layer 122 is formed by printing a solution containing a precursor of silicon oxide (SiO2) such as polysilazane, polysiloxane, tetraethyl orthosilicate, drying, and heat treatment. I can. As another example, the auxiliary substrate layer 120 may be formed by printing a solution including a precursor of aluminum oxide (Al2O3) such as trimethylaluminium, drying, and heat treatment. As another example, the back channel protective layer 122 may be formed by printing a solution containing a precursor of an oxide having good insulating properties such as zirconium oxide (ZrO2) or titanium oxide (TiO2), drying, and heat treatment. As another example, the back channel protective layer 122 may be formed by printing and curing a polymer having good insulating properties. It is preferable to use a material having a low adhesion to the separation layer 102 for the back channel protective layer 122.

Referring to FIG. 9, the flexible substrate 200c according to the present example includes a substrate film 114 between the substrate film 114 and the active pattern 112, between the substrate film 114 and the active pattern 112, and the substrate film 114 And the source electrode SE, between the substrate layer 114 and the drain electrode DE, between the substrate layer 114 and the gate insulating layer 107, and between the substrate layer 114 and the gate electrode ( GE) may further include a gas barrier layer 124 interposed between. The gas barrier layer 124 may be formed of a dense inorganic film, organic film, or organic-inorganic composite film. The gas barrier layer 124 may be formed by applying a precursor solution and then curing or heat treatment. Alternatively, the gas barrier layer 124 may be formed by a vapor phase method such as chemical vapor deposition (CVD), atomic layer deposition (ALD), thermal evaporation, and sputtering. The gas barrier layer 124 is a single inorganic material thin film such as silicon oxide (SiO2), silicon nitride (SiNx), silicon oxynitride (SiOxNy), titanium oxide (TiO2), zirconium oxide (ZrO2), or aluminum oxide (Al2O3). It may include. In addition, the gas barrier layer 124 may include a single organic material thin film such as polyacrylic, polyurethane, epoxy polymer, polyimide, polypropylene, fluorine-containing polymer, and silicone polymer. The gas barrier layer 124 may include a multilayer thin film composed of one or more inorganic material thin films and one or more organic material thin films.

Referring to FIG. 10, the flexible substrate 200d according to the present example may include a first protective film 130 and a second protective film 132 respectively covering the upper and lower surfaces of the substrate film 114. . In FIG. 10, both the upper and lower surfaces of the substrate layer 114 are covered with protective films 130 and 132, but only one of the upper and lower surfaces of the substrate layer 114 is covered with a protective film, and the other surface is It may be exposed. The first protective film 130 and the second protective film 132 may be attached to improve mechanical properties of the flexible substrate 200d and protect the substrate.

As described above, in the method of manufacturing a flexible substrate and a flexible substrate according to embodiments of the present invention, a flexible substrate having more stable thin film transistor characteristics and stable insulating characteristics can be provided at a low cost.

In the above, embodiments of the present invention have been described with reference to the accompanying drawings, but those of ordinary skill in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features. You can understand that there is. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting.

100: carrier substrate
102: separation layer
104: gate catalyst pattern
106: gate plating pattern
107: gate insulating film
108s: source catalyst pattern
110s: source plating pattern
108d: drain catalyst pattern
110d: drain plating pattern
112: active pattern
114: substrate film
120: auxiliary substrate film
122: back channel defense layer
124: gas barrier layer
130, 132: protective film
GE: gate electrode
SE: source electrode
DE: drain electrode

Claims (14)

Forming a separation layer on the carrier substrate;
Printing a gate catalyst pattern on the separation layer and forming a gate plating pattern on the gate catalyst pattern;
Forming a gate insulating layer on the gate plating pattern;
Printing a source catalyst pattern and a drain catalyst pattern spaced apart from each other on the gate insulating layer, and forming a source plating pattern and a drain plating pattern on the source catalyst pattern and the drain catalyst pattern, respectively;
Forming an active pattern covering the source plating pattern, the drain plating pattern, and the gate insulating layer exposed therebetween;
Forming a first flexible substrate film covering the entire surface of the carrier substrate on which the active pattern is formed;
Removing the separation layer and the carrier substrate; And
After removing the carrier substrate, a method of manufacturing a flexible substrate comprising the step of forming a protective film covering at least a portion of the first substrate film. The method of claim 1,
The step of forming the gate insulating layer,
A method of manufacturing a flexible substrate comprising the step of printing and heat treating a precursor solution of a material constituting the gate insulating layer. The method of claim 1,
Before forming the gate catalyst pattern, the method of manufacturing a flexible substrate further comprising forming a second flexible substrate film on the separation layer. The method of claim 1,
Before forming the first substrate film, the method of manufacturing a flexible substrate further comprising forming a back channel defense layer covering the active pattern. The method of claim 1,
Before forming the first substrate film, the method of manufacturing a flexible substrate further comprising forming a gas barrier layer covering the entire surface of the carrier substrate on which the active pattern is formed. delete The method of claim 1,
The separation layer is a method of manufacturing a flexible substrate formed of a material different from that of the gate plating pattern. A first substrate film;
An active pattern disposed in the first substrate film;
A source electrode and a drain electrode disposed in the first substrate layer and spaced apart from each other by the active pattern;
A gate electrode disposed in the first substrate film and spaced apart from the source electrode and the drain electrode; And
And a gate insulating film interposed between the gate electrode and the source electrode and between the gate electrode and the drain electrode,
The gate electrode includes a gate catalyst pattern and a gate plating pattern,
The source electrode includes a source catalyst pattern and a source plating pattern,
The drain electrode is a flexible substrate including a drain catalyst pattern and a drain plating pattern. The method of claim 8,
The gate catalyst pattern is a flexible substrate having an upper surface coplanar with the upper surface of the first substrate layer. The method of claim 8,
A flexible substrate in which upper surfaces of the source catalyst pattern and the drain catalyst pattern are coplanar with the upper surface of the active pattern. The method of claim 8,
A flexible substrate disposed on the first substrate layer and further comprising a second substrate layer in contact with the gate catalyst pattern. The method of claim 8,
The flexible substrate further comprising a back channel protective layer interposed between the first substrate layer and the active pattern. The method of claim 8,
Between the first substrate layer and the active pattern, between the first substrate layer and the source electrode, between the first substrate layer and the drain electrode, between the first substrate layer and the gate insulating layer, and between the first substrate layer and Flexible substrate further comprising a gas barrier layer interposed between the gate electrode. The method of claim 8,
Flexible substrate further comprising a protective film covering at least a portion of the first substrate film.

Images